Clutch master with larger bore?

[DRIVEN]

I'm hoping to find a clutch master with a larger bore than 5/8" for something I want to try on my 510. I spent a few minutes on Rockauto poking around in different years and models but found nothing. Anyone know a bolt-in (or close to it) master in 11/16" or even 3/4" bore? Closest thing I could find was a single pot brake master cylinder from a 521 in 3/4".

[ggzilla]

280ZX

[datzenmike]

The bolt pattern is diagonal on the zx master. If it has the same spacing I guess it would work tilted slightly if you keep the cap on. ;)

[ggzilla]

Some guys have drilled new holes.

 

Datsun A10 looks the same as 510, but is 13/16". It has the vertical mounting holes, same 10x1 bottom outlets. Push-rod depth is a little different but shims/spacers and push-rod length is always an issue when swapping.

[DRIVEN]

Datsun A10 looks the same as 510, but is 13/16".

Really? I looked it up and it listed 5/8" bore. Sure you weren't reading the brake master bore? These all seem to share the same Dorman number:

NISSAN 200SX (1977 -1979)

NISSAN 240Z (1970 - 1973)

NISSAN 260Z 1974

NISSAN 280Z (1975 - 1978)

NISSAN 510 (1968 - 1981)

NISSAN 620 PICKUP (1972 - 1979)

NISSAN 810 (1977 - 1980)

NISSAN B210 (1974 - 1978)

NISSAN F10 (1976 - 1978)

[ggzilla]

my bad, was looking at Brake master.

[DRIVEN]

Thanks anyway guys. Was hoping I'd just overlooked an obscure OEM part. Looks like I'll have to go Wilwood or Afco. They both list a 3/4".

[ggzilla]

Yes, a larger master will move the clutch lever farther, so you can adjust the pedal closer to the floor. Let us know how it works out. The only downside is you will have to push harder, but it will be good exercise.

[banzai510(hainz)]

downside is you will have to push harder, but it will be good exercise

 

Correct!!!!!!!!!!

 

 

Im wondering why go bigger bore.?

[datzenmike]

Maybe has the wrong collar on the clutch arm. Too sort needs more travel.

[DRIVEN]

That may be true too. My particular situation is probably more a result of my Nissan/GM hybrid clutch assy. It works okay but I think it needs just a touch more travel. It's maxed for throw at the pedal end but it's always been a bit stiffer to shift than it should be and the pedal has to be ALL the way to the floor to shift smooth. If I actually had carpet it would likely grind. Since the stock master has recently developed a seeping seal, I though now would be a good time to upsize the bore. I'd really like 11/16". I can limit the pedal travel to keep from moving too much volume and popping the end of the slave apart. I'm afraid 3/4" might be too much. If you've ever seen the size of my stumpy legs, you probably wouldn't be concerned about pedal effort :blush: .

My throwout bearing has started making noise intermittently too so maybe I'll take some measurements and change collar size if necessary. IIRC it's pretty close already. Are the collars readily available?